Method and apparatus for lubricating conveyor systems and the like

ABSTRACT

A system is disclosed for lubricating conveyor chains utilizing foamed lubricant in the form of liquid soap. The foam is formed by feeding controlled streams of air and liquid lubricant to the bottom of a bead chamber so as to create small bubbles. The foam is then passed through a restriction to an expansion chamber where the bubbles are enlarged. The finished foam is then delivered to various stations in contact with the conveyor chains. The system permits careful control with respect to the aeration, i.e., the amount of foam.

United States Patent [72] Inventor Robert L. Batchelor 412 Beach Road, Venice, Fla. 33595 [21 Appl. No. 840,259 [22] Filed July 9, 1969 [45] Patented Apr. 27, 1971 [32] Priority July 22, 1968 [3 3] Australia [31 41024/68 [54] METHOD AND APPARATUS FOR LUBRICATING CONVEYOR SYSTEMS AND THE LIKE 6 Claims, 1 Drawing Fig.

[52] US. Cl 184/15R, l59/DIG 4, 261/DIG 26 [51] Int. Cl F16n 7/24 [50] Field oI'Search 184/15, 15 (A), 15 (B); 159/(Digest 26); 252/3595; 261/(Digest 26); 239/343; 169/15 [56] References Cited UNITED STATES PATENTS 2,090,727 8/1937 Gosmann 169/15X 2,864,714 12/1958 Dixon,Jr.etal 261/Digest26 2,887,275 5/1959 Dixon,Jr.etal 169/15X 3,148,747 9/1964 Batchelor 184/15 3,322,684 5/1967 Gibsonetal 252/359 3,388,868 6/1968 Watsonetal 261/Digest26 FOREIGN PATENTS 644,103 7/1962 Canada 261/Digest26 Primary Examiner-Manuel A. Antonakas Attorney-Curtis, Morris & Safford ABSTRACT: A system is disclosed for lubricating conveyor chains utilizing foamed lubricant in the form of liquid soap. The foam is formed by feeding controlled streams of air and liquid lubricant to the bottom of a bead chamber so as to create small bubbles. The foam is then passed through a restriction to an expansion chamber where the bubbles are enlarged. The finished foam is then delivered to various stations in contact with the conveyor chains. The system permits careful control with respect to the aeration, i.e., the amount of foam.

PATENTED mam 3576234 SOAP v INVENTOR. Robert L. Botchelor ATTORNEYS METHOD AND APPARATUS FOR LUBRICATING CONVEYOR SYSTEMS AND THE LIKE Heretofore, lubrication systems employing dilute soap solutions have been used to lubricate conveyors in dairies, breweries, and other bottling plants because of sanitation requirements. Certain such systems were developed by me in which an admixture of soap solution and air is deposited on the the use because of shortcomings in the lubricating functions .and operation. More particularly, wastage of the lubricant frequently occurs because the solution does not properly adhere to the chain and runoff and dripping results. Additionally, the air-soap solution is often mixed in improper proportions, due to lack of control exercised over aeration, and the foam lubricant has tended to climb the containers on the conveyor and interfere with the inspection or impair the labelling.

-While in some instances it is desirable to have highly aerated foam which climbs the container walls, such as in conveyors transporting bottles to be washed, at other times, only slightly aerated solutions should be applied. Obviously, it si desirable to control precisely thedegree of aeration or foaming of soap solution supplied as a lubricant to satisfy the exact requirements of eachindividual conveyor. It is an object of the present invention to provide that control.

Another problem encountered with foam lubricants is the difficulty of air penetration of the soap solution itself. As yet no effective apparatus has been introduced which insures the admixing of air with exceedingly gas-impervious soap solu tions..

Thepresent invention overcomes'the stated deficiencies in theprior art and has as its primary objective the method of and apparatus for exercising control over the degree of aeration in a foam lubricant. More particularly, the present invention envisions admixing the air and soap components of the lubricant, generating therewithin a high level of gas penetration and thereafter subjecting the admixture to a pressure drop to effect complete gas incorporation into the lubricant.

The various features of the apparatus of this invention will become apparent from the following detailed description set forth in connection with the accompanying drawing which relate to the preferred embodiment of the present invention and 'is given by way of illustration.

The single FIGURE is a longitudinal cross-sectional view of one embodiment of the present invention, with the conveyor represented schematically.

Reference is now made to the preferred embodiment of the present invention as shown in the FIGURE. A metering valve 1 is interposed between a source of compressed air at approximately 20 p.s.i., and a conduit 16. The conduit is threaded in the solid lower portion 20 of a cylinder 2, whose axis is preferably vertical. A passage 4 in portion 20 has its axis concentric with the axis of chamber 2 and communicates through a restrictor port 3 with conduit 16.

The soap solution is recieved through a metering valve 5 from a source of soap solution, preferably a high quality coconut oil at 20 p.s.i., and a conduit 17 which is threaded 'into portion 20 of the cylinder diametrically opposite to conduit l6. Conduit 17 communicates with passage 4 through a I restrictor port 6.

The passage 4 extends upwardly into a cavity 7 whose axis is concentric with the cylinder axis, and which extends to the top of the cylinder and is closed by a plastic cap 13. Suspended from cap 13 within cavity 7 by a stem is a restrictor disc 9 which forms a peripheral passage 18 of narrow width, along the cavity wall. Disc 9 divides cavity 7 into a foaming chamber 19 beneath the disc and an expansion chamber 21 above the penetration, and breaks up the bubbles of air. Hence, as the air and soap solution move upwardly through chamber 19, a uniform small-bubble foam is fonned which passes through the annular passageway 18 into the expansion chamber 21. Within expansion chamber 21, the pressure is reduced causing each of the bubbles to expand in a uniform manner thereby producing a thoroughly satisfactory foam.

Extending from chamber 21 is a plurality of radial bores or ports 11 into which distribution tubes or conduits 23, 24, etc. are threaded. The lubricating solution, in the foamed condition, passes through these tubes to the appropriate zones of application to the chain conveyor.

Plastic cap 13 closes the top of cavity 7 and also supports disc 9 through stem 10. The cap includes a seal portion 15 which is snugly received in the top of the cavity and the top portion 14 which is mounted on the top of cylinder 2 by .screws (not shown). The heads 8 within the chamber 19 have a diameter greater than the width of the peripheral passage 18 to obviate escape through the upper end of the cavity. Each of the conduits illustrated in phantom extends to a lubricating chamber 29, 30, etc. through which a chain 31, 32, etc. passes and in which foam lubricant is deposited over the chain.

In operation, air and soap solution are injected through ports 3 and 6 into passage 4 and pass upwardly at high velocity and enter chamber 19 axially thereof. The air flow in passage 4 produces a venturi efiect at the small diameter port 6 and causes the air to pick up'the desired amount of soap solution. The pressure drop in chamber 19 causes expansion of the air and agitates the air and soap to form a foam or lather. The level of air penetration at this stage is substantial, but not complete, and as the foam passes upwardlythrough the body of packed beads 8, the admixture continues to form. As the lubricant moves through the peripheral passage 18, it gains velocity and is received in enlarged passage 21 where it again undergoes a substantial-pressure drop. At this stage, even the mostgas-impervious soap solution will have fully incorporated the air supplied to the admixture and the degree of aeration approaches percent. The foam lubricant is then conveyed through bores 11 and tubes 23, 24, etc. for deposition on the appropriate chain conveyor.

In the illustrative embodiment, the foamed lubricant is delivered through four distribution tubes 23, 24, etc. to separate zones 29, 30, etc. on the conveyor. In many installations it is desirable to deliver lubricant at a greater rate to one zone than another. The distribution tubes are of relatively small diameter so that they impose a predetermined restriction to the flow of foamed lubricant through them. Hence the rate at which lubricant is delivered to any particular zone may be varied relative to the rate delivered to the other zones by changing the length of its distribution tube. Accordingly, in the system the tube extending to the zone requiring the greatest amount of lubricant is the shortest of the four tubes. The lengths of the other tubes are then of greater length, the additional length of each being sufficient to provide the additional resistance to flow which will satisfy the foam requirement for that zone. The tubes are of flexible plastic so that excess tube length can be wound into a helix. It is understood that the rate of flow to all of the zones in the system may be increased or decreased by an appropriate change in the air and soap pressures. in the illustrative embodiment, both of those pressures are maintained at 20 pounds per square inch, but those can be varied to change the relative amounts of air and soap solution, thus changing the characteristics of the foam.

Many factors are considered in determining the amount of air supplied to the admixture by valve 1 which controls foam aeration based on the demands imposed on the chain and use to which it is put. For example, lubrication on a conveyor transporting bottles to electronic inspection apparatus should have little or no foam to avoid interference with the device and also to avoid improper rejection by foam detection. Accordingly, virtually no aeration is injected into the lubricant. For bottles conveyed to a washer, a heavily aerated lubricant should be utilized so that foam will climb the bottle to facilitate movement of same into the washer pocket. Conveyors transporting bottles to labeling machines should have lubricants of only slight aeration to avoid interfering foam climbing. Chains conveying containers to a pasteurizer require highly aerated lubrication to counteract the moisture on the chain to avoid dripping and runofi". Finally, chains used for outdoor summer work require lubrication of very little aeration to overcome dehydration. Obviously, the use determines the amount of air incorporated in the lubricant.

Although only one embodiment of the present invention has been illustrated and described, it will be evident to those skilled in the art that various modifications may be incorporated into the details of productions without departing from the principles herein set forth.

lclaim:

1. In a foam lubricating system for chain conveyors and the like, the combination of, means for supplying gas under pressure, means for supplying foam-forming solution under pressure, passage means communicating with said gas supply means and said foam-forming solution supply means, a foamfonning chamber adapted to receive said gas and said solution from said passage means and to direct them together along a foam-forming path, gas-and-liquid contact means positioned within said chamber along the upstream portion of said path, producing a first pressure drop within said chamber, restrictor means positioned along said path downstream with respect to said gas-and-liquid contact means, and an expansion zone in said chamber downstream from said restrictor means, said restrictor means providing a second pressure drop along said path in said expansion zone to induce gas penetration in said liquid to produce said foam, and means to deliver foam from said expansion chamber.

2. Apparatus as described in claim 1 wherein said chamber comprises an elongated passageway and said restrictor is formed by a disc centrally positioned within said passageway with said path extending through an annular passageway around said disc.

3, Apparatus as described in claim 2 wherein sad gas-andliquid contact means comprises a plurality of beads positioned within said chamber, and said restrictor means includes a stem portion connected to and supporting said disc and connected to a closure wall of said chamber.

4. Apparatus as described in claim 3 which includes a plurality of narrow-diameter tubes which extend to various zones where lubricant is desired and wherein the length of each tube is such as to provide a controlled restriction to the flow therethrough.

5. Apparatus as described in claim 3 wherein said chamber is generally cylindrical and is axially positioned within an elongated member having an inlet bore for gas and solution extending axially into the end of said chamber, a pair of radial inlet passageways connecting with said axial bore one of which is connected to pass said gas and the other of which is downstream thereof and is connected to pass said solution, and control means to control the supplying of gas and solution in accordance with a predetermined cycle.

6. The method of forming a foam lubricant for chain conveyors and the like comprising, the steps of, supplying gas and foam solution to a flow path, producing a first pressure drop inducing gas penetration into said foam solution to produce bubble formations, increasing the velocity of said bubble formations along said path, subjecting said bubble formations to a second pressure drop downstream of said increased velocity to induce further gas penetration in said foam solution, and conveying said bubble formation to a remote location for use. 

2. Apparatus as described in claim 1 wherein said chamber comprises an elongated passageway and said restrictor is formed by a disc centrally positioned within said passageway with said path extending through an annular passageway around said disc.
 3. Apparatus as described in claim 2 wherein sad gas-and-liquid contact means comprises a plurality of beads positioned within said chamber, and said restrictor means includes a stem portion connected to and supportiNg said disc and connected to a closure wall of said chamber.
 4. Apparatus as described in claim 3 which includes a plurality of narrow-diameter tubes which extend to various zones where lubricant is desired and wherein the length of each tube is such as to provide a controlled restriction to the flow therethrough.
 5. Apparatus as described in claim 3 wherein said chamber is generally cylindrical and is axially positioned within an elongated member having an inlet bore for gas and solution extending axially into the end of said chamber, a pair of radial inlet passageways connecting with said axial bore one of which is connected to pass said gas and the other of which is downstream thereof and is connected to pass said solution, and control means to control the supplying of gas and solution in accordance with a predetermined cycle.
 6. The method of forming a foam lubricant for chain conveyors and the like comprising, the steps of, supplying gas and foam solution to a flow path, producing a first pressure drop inducing gas penetration into said foam solution to produce bubble formations, increasing the velocity of said bubble formations along said path, subjecting said bubble formations to a second pressure drop downstream of said increased velocity to induce further gas penetration in said foam solution, and conveying said bubble formation to a remote location for use. 